The Mary Celeste, in her earlier days as the Amazon (Public domain image)

In 1872, a ship was found adrift in the Atlantic Ocean, in near-perfect condition but for one problem: there was nobody aboard. In time, the story of the Mary Celeste became one of the most famous riddles of the sea. Over the years, many have offered solutions for what happened to the crew. But are any of them correct?

As is the case with so many of the mysteries we examine here on Skeptoid, the story of the Mary Celeste was an actual event that was largely forgotten until an imaginative author revived and exaggerated it for popular audiences. This time, the author was a young man who would later be knighted as Sir Arthur Conan Doyle for his Sherlock Holmes books. It was a short story written under the pseudonym W. Small for the January 1884 issue of Cornhill Magazine, entitled "J. Habakuk Jephson's Statement". Conan Doyle dramatized the Mary Celeste's story, adding such touches as meals laid out on the table, tea boiling on the stove, and the ship sailing boldly into the harbor at Gibraltar with nobody at the helm. Today, most people who have heard of the ship think these details are part of what actually happened. They aren't.

Conan Doyle's was only the first of many such treatments. A 1913 magazine article was the forged account of a man named Fosdyk who claimed to have been a stowaway on board the Mary Celeste, witnessed the entire crew fall overboard as they pressed against the rail to watch three of the men have a swimming race, then managed to be the only one not eaten by sharks and eventually washed ashore on Africa. In the 1920s, an author named Keating forged an article for Chamber's Journal telling the story of a man named Pemberton who survived. Keating soon expanded the fictitious Pemberton's tale into a book called The Great Mary Celeste Hoax. Unfortunately, the book's success became its downfall: Interviews with Pemberton were widely sought. Keating tried to weasel his way out with excuses, and even offered a picture of his own father as a photograph of Pemberton; but it was soon discovered that he made the whole thing up.

The Mary Celeste was a small merchant brigantine of 33 meters and 282 gross tons. She'd just been acquired by a small group of investors, among whom was the ship's one-third owner, Captain Benjamin Briggs. Joining him on board were his wife and baby daughter, plus seven sailors. They left port from Staten Island, New York in November of 1872, fully laden with cargo bound for Genoa, Italy. The cargo was 1,701 wooden barrels of pure grain alcohol, intended to fortify cheap Italian wines. America's vast corn fields made it the cheapest producer of grain alcohol at the time, and it made good economic sense for Italy to buy it and ship it all the way from the United States.

The voyage was relatively uneventful according to Captain Briggs' log entries, and the fine weather was confirmed by the captain of another ship sailing one week behind. Captain David Morehouse commanded the Dei Gratia, a similar brigantine laden with petroleum. Briggs and Morehouse had sailed together for many years and knew each other well, and it was a happy coincidence that the two friends found themselves on nearly identical voyages.

But almost halfway between the Azore Islands and Gibraltar, Morehouse made an unhappy discovery. The Dei Gratia unexpectedly caught up with the Mary Celeste, finding her adrift. Morehouse sent a party to investigate, and found the Mary Celeste unmanned. It was a bizarre find; there were no obvious signs of trouble and all appeared to be in order. But there were a few interesting clues.

The Mary Celeste had been equipped with a yawl, and though that term usually describes a type of sailboat, in this case it refers to a ship's rowboat capable of being rigged for sailing. The yawl was normally stored atop the main cargo hatch between the two masts, but was gone; and the railings on one side of the ship had been lowered indicating that the yawl had been launched normally. The other two cargo hatches — the forehatch on the foredeck and the lazarette hatch, above a small compartment aft — had both been removed and were stowed, exposing the cargo of alcohol.

When Morehouse found the ship, it was flying minimal sails, the fore lower topsail and two jibs. Modern analysis has confirmed that Morehouse found it just about where it would have been expected to be, driven primarily by currents, if it had been under no helm control since passing the Azores. Interestingly, the main peak halyard, the stoutest line on the ship, was missing; and it was very likely the same rope that was found cleated off and trailing in the water behind the ship. There was a significant amount of water in the bilge and cabins of the ship, but this was believed to be consistent with the open hatches and an opened skylight. The Mary Celeste had tossed about for at least ten days since its last log entries, in freshening weather that had compelled the crew to shorten sail; and so it was not surprising that it had taken on some water. As its stores were in good shape and it was perfectly seaworthy, Morehouse sent a skeleton crew aboard the Mary Celeste and brought it to Gibraltar, where the loss was reported and investigations took place for purposes of insurance and salvage. When the cargo was unloaded and examined, nine of the barrels of alcohol were empty: undamaged, yet empty.

Early theories quickly focused on the relationship between Briggs and Morehouse, and charges of conspiracy and insurance fraud were flung about; but these theories made no sense from a profit standpoint. For a while, some believed piracy had taken place, or that perhaps Briggs' crew had drunkenly mutinied against him; but all of these stories crumbled under scrutiny and lack of evidence that would have been expected.

Since then, even more suggestions have come from the fringe, pointing to exotic causes for the abandonment, like waterspouts and rogue waves. One in particular, David Williams, proposes that a "seaquake" struck the ocean floor. He states that the US and British navies know that such quakes can destroy surface vessels with powerful shockwaves, but that they cover it up so it's not generally known. Williams' theory is that this sudden shaking released embers from the ship's stove, so the crew fled the ship fearing the embers would ignite the store of alcohol. Williams states that there are numerous examples of ships sustaining heavy damage from such shockwaves, but as no damage was noted on the Mary Celeste, his seems an arbitrary explanation.

A few pieces of physical evidence strongly suggest what has emerged as the favorite theory, based on those nine empty barrels discovered in Gibraltar. The reason they were empty would have been clear to any cooper. All of those many barrels were of white oak, except for those nine, which were of red oak. Of the species of wood sold as white oak, the majority have occluded pores. This makes the wood watertight, which is why white oak is used for wine barrels and other barrels intended to hold liquid. The pores in the wood of the twenty or so species of red oak, on the other hand, are open; allowing liquids to seep through the wood. Consequently, red oak barrels should only be used for dry goods. But, for some reason, Meissner Ackermann & Co. (owner of the alcohol) used nine of the wrong type of barrel.

At some point in the voyage, or possibly even before, these barrels would have become soaked through. Alcohol evaporates quite quickly, so the smell would have permeated the ship's cargo hold. No record remains of where in that vast pile of 1,701 barrels the nine red oaks were found, but chances are that most of them were hidden from view. A visual inspection of the cargo hold probably would have found nothing, making it impossible to tell the extent of the leakage, but that smell would have been everywhere. This is also evidenced by the removed deck hatches; the crew were undoubtedly trying to vent the flammable fumes. But alcohol vapor is heavier than air, so it's unlikely that venting the deck hatches would have done much to dispel it.

The crew had to have feared that an explosion or fire was imminent. The yawl was launched and everyone on board removed to it. This was not done in a panic or haphazardly, but rather urgently and efficiently. The captain had the sense to collect his sextant and marine chronometer, necessary for navigating; but everything else on board that was not essential was left behind. No strong evidence suggests an answer to the question of whether they intended to completely abandon the ship, or to simply sit at a safe distance until they figured the danger was past. They took the precaution of using the strongest line they had to secure the yawl to the Mary Celeste, but in some unknown circumstance, the line was not secure or became severed. The few sails still set on the ship were enough that the yawl's rowers could not keep up. Once he saw they would not be able to catch the ship, the captain headed for Santa Maria Island in the Azores. And, as was all too often the end of such deep sea open boat voyages in those days, they never made it, and were ultimately swallowed by the Atlantic Ocean.

Over the next ten days, the Mary Celeste rocked in the breeze with its open hatches. The last of the alcohol evaporated away, and no one in Morehouse's party reported smelling anything. It's a certainty that all nine barrels, some 450 Imperial gallons, escaped as fumes while the Mary Celeste was at sea.

In 2006, Dr. Andrea Sella, a chemist at University College London, conducted an experiment to recreate conditions that he believes may have prompted Briggs to evacuate. Sella filled a compartment with cubes of paper and butane gas, then sparked it. The resulting combustion produced a sudden flash of flame that was visually dramatic, but was cool and quick enough that the paper was not scorched. Dr. Sella theorized that perhaps such a flash had happened in the Mary Celeste's cargo compartment, frightening the crew into fearing that a much larger explosion may well have been imminent. The ethanol vapors in the Mary Celeste's hold would burn even cooler and quicker than butane, though probably much less dramatically, with a blue or invisible flame, unlike like the butane's yellow flash. But it certainly would have been every bit as alarming to the crew, if it had happened.

Without any reasonable doubt, the cause of the disappearance of the Mary Celeste's crew was voluntary abandonment. We can't be certain what prompted the evacuation, but there seems little reason to speculate beyond what's best supported by the evidence: powerful and dangerous fumes from the alcohol-soaked red oak barrels. Briggs' action, though ultimately disastrous, was more than reasonable at the time.